You may experience difficulties in mounting the mailbox stores or public folder stores if you do not maintain these permissions for these groups and accounts. The following error messages and events indicate this type of problem:

An internal processing error has occurred. Try restarting the Exchange System Manager or the Microsoft Exchange Information Store service, or both.

MAPI or an unspecified service provider. ID no: 00000476-0000-00000000.

Information Store (2520) An attempt to determine the minimum I/O block size for the volume "[drive:\]" containing "[drive:\]Exchsrvr\Mdbdata\" failed with system error 5 (0x00000005): "Access is denied." The operation will fail with error –1032 (0xfffffbf8).

The MAPI call 'OpenMsgStore' failed with the following error: The Microsoft Exchange Server computer is not available. Either there are network problems or the Microsoft Exchange Server computer is down for maintenance. The MAPI provider failed. Microsoft Exchange Server Information Store ID no: 8004011d-0526-00000000.

You may also encounter problems when mounting public folder stores if you have turned off the Allow inheritable permissions from parent to propagate to this object option for the public folder hierarchy. The following error messages indicate this type of problem:

The store could not be mounted because the Active Directory information was not replicated yet.

The Microsoft Exchange Information Store service could not find the specified object. ID no: c1041722